Dental lighting fixture



A ril 19, 1932. J: HANSEN 1,854,302

DENTAL LIGHTING FIXTURE Filed May 2, 1931 2 Sheets-Sheet l #13 INVENTOR v .7

ORNEY I April 19, 1932.

J. HANSEN 1,854,302

DENTAL LIGHTING FIXTURE Filed May 2, 1931 2 Sheets-Sheet 2 fl .3 4 'j INVENTOR ATTORNEY Patented Apr. 19, 1932 UNITED STATES PATENT OFFICE JASPER HANSEN OF DECATUR, ILLINOIS, ASSIGNOR TO FARIES MANUFAGTURINGj-i COMPANY, OF DECATUR, ILLINOIS,-A CORPORATION OF ILLINOIS DENTAL LIGHTING- FIXTURE Application filed May 2, 1931.

My invention relates to a fixture which is primarily designed for use by dentists, although it will be obvious from the hereinafter contained design that it is not limited to such use. In dentistry it is frequently necessary for the operator to work on teeth in different locations of the patients mouth and good light is essential in order to good work.

My invention has for its object to provide a device which can be swung into practically any position and which will remain in such position until manually moved therefrom.

A further object is to provide for the loni 16 gitudinal adjustment of said light without permitting the rotation'thereof.

A further object is to provide automatic operative means to hold said light in any desired angular position.

A further object is to provide means to prevent a complete revolution of the light and thus avoid any possibility of twisting the electric wires and causing ashort.

Y My means of accomplishing the foregoing objects may be more readily understood by having reference to the accompanying drawings in which Fig. 1 is a side elevation of my improved light, the various positions to which it may be moved, being indicated by dotted lines;

Fig. 2 is a top or planview of the same; Fig. 3 is an enlarged detail view of the base; and

Fig. 4 is an enlarged detail view of the universal joint which carries the light.

Similar reference numerals refer to similar parts throughout the entire description.

As shown in the drawings, the device consists of a base 1 which is designed to be suitably attached to a wall 2 or other convenient support. This base 1 has two outwardly ex- 7 tending lugs 3 and l. These lugs are provided with apertures 5 and 6 in which is mounted a pin 7 which passes through an opening 8 on the one side 9 of an annular memberlO. A coil spring surrounds the pin 7 and exerts a pressure against the lugs 3 and 4. This coil spring fits so closely into the opening 8 that the expanding of the coils by its compression produces frictional engage- Serial No. 534,526.

ment with the walls-of the opening 8 so that while the annular member 10 may be swung on the pivot pin 7, as clearly seen in Fig. 2,

there is sufficient friction to hold it in the 7 position in which it is placed untilmanually" moved to another. Inside the annular member 10 I mount a disc 11. This disc 11 has two dlameterically opposite notches 12 and 13 formed in its periphery. In the notch 12 I means to carry the electric wires to the lamp (not shown) Another arm 25 is telescopically mounted in the forked arm 20,1a suitable frictional clutch 26 of standard construction being provided to hold it in the extended position as shown in Fig. 1 by the dotted lines. Obviously it can be extended or retracted as desired. Secured to the end of the telescopic arm 25 is a universal joint formed, as clearly seen in Fig. 4, of a sleeve 26, having a closed end 27 which forms part of asoclret for a ball 28. This ball is formed with a central opening therethrough for the passage of the electric wires indicated by the heavydotted line formed of tubing thus providing convenient I Fig. 4. A plug 29 is slidably mounted in the sleeve 26, its inner end'being concave forming a socket for the ball 28. Threads 30 are cut on the end of the sleeve 26, preferably on its internal wall, and a threaded plug 31 having a hexagon head 32 is screwed into the threads 30 and provideconvenient means for adjusting the tension of a coil spring 33 mounted intermediate the two plugs 29 and 31. It is apparent as the tension of the spring 33 is increased, that the friction upon the ball 28 will be increased and this can be so regulated that the joint, and in turn the lamp, can be held in any desired position. A standard electric socket 34 is suitably attached to the sleeve 26 and is enclosed in a canopy 35 which carries a shade 36 designed to enclose the lamp (not shown).

If one were to rotate the universal joint completely around on its axis it is obvious the wires would be twisted and danger of a short-incurred. I preventthis-by forming a groove 37 inthc ball 28 .andmounting a detent 38 in the groove which engages a stop pin 39 fastened to the sleeve 26. Thus while the lampmay be freely swung about 3 its axis it cannot go-beyond the pointwherethe detent 36 engages the pin 39.

Having described my invention what 'I regard as new and desireto secure-byLetters Patent of the United States,'is:

.1. In a device of the character described for-electric lamps in whichua lamp is supported atthe outer end of atelescoping tube,

the lamp socket being connected to the tube by a universal joint, the tube being polygonal in crosssection, and iafforkedsarm in which said tube I is slidably mounted, characterized iby-the factthatthefork on said arm is'provided witlnplates adaptedtoengage a disk :mounted in -anaannnlar member, a base to which said-annular member is pivotally secured; there belng notches cut in the periphery ofsaid disk, a springrpressed dog in each notch which engages the lnnersurface of said annular member when the disk is rotated in one direction whereby said arm :will be held in any position to-which it is moved.

.;2. :In =a device .of the-.cl aracter descrlbed for electric lamps inwhichadamp is sup- ,ported at the outer end of a telescoping tube,

the lamp 1 socket being connected to the tube by -a universal joint, theitube being polygonal -1n-cross section, and aforked arm in which said' tube is slid-ably mounted, characterized rbyithe-lfact that the fork on said arm-is provided 1with uplatesadapted 'toengage a disk mounted in an annular amember, a base to which saidaannular member. 1s p1votally secured, a spring to cause frictional-engagement betweenthe baseuand the annular member, there being notchescutin the periphery of said disk, a spring pressed dog in each notch which engages the, inner surface of said anntilanmember when the disk is rotated in one direction whereby said arm will beiheldin any position to which it is moved.

3. Ina device ofthe character described for electric'lamps in which a lamp is support ed at the outer end of a-telescoping tube, the

lamp socket being connected to the tube by a universal joint,--thetube being polygonal in crosssection, anda forked arm in which .,a base towhich said annular memberis pivotally secured, there, being notches cut lnthe periphery of said disk, ,a springpressed .dog in-eaeh notch which engages the inner surface ,by the fact that the fork on said arm is provided with plates adapted to engage a disk mounted in an annular member, a base to which said annular member is pivotally secured, a lateral projection on said annular member, there being a vertical aperture in said projection, a coil spring in said aperture to cause frictional engagement between thebase and the annular member, there being notches cutin the periphery of said disk, a

spring pressed dog in-each notch which engages the inner surface of said annular member when the disk is rotated in one direction whereby said arm will beheld in'any pos1- tion to which it is moved.

5. In a device of the character described for electric lamps in which a lamp is supported at the outer end of a'telescoping tube, the lamp socket being connected to the tube by a universaljoint, the tube beingpolygonal in cross section, and a forked arm in which .said tube is slidably mounted, characterized by the fact that the fork on said arm ispro- .vided with plates'adapted" to engage-a disk:

mounted in an annular member, a basevto which said annular member is pivotallysecured, said disk being arranged to rotate freely; in one direction, yieldablefrictionmeans mounted. in the disk which resistits move-' ment in E the opposite direction whereby said disk and arm will be held in vanypositionto iwhich it is moved.

6. An adjustable dental lighting fixture'in which alamp issupported at the outer end-of; a telescoping tube, the tube-being-polygonal in cross section and slidable in a forked arm which is frictionally secured to a disk mounted in an annular member pivotally attached to a base, said disk having yieldable frictional means which permit its rotation freelyin one direction but resists its movement in' the opposite direction, characterized by the fact that the lamp socket is connected to the tube by a universal joint comprising a sleeve closed at one end to form a socket, a ball which fits said socket, aplug one end of which fits said ball slidably mounted in said sleeve, a plug threaded-into the openend of said sleeve, a coil spring intermediate said plugs, whereby. screwing in said threaded plug will increase the friction between said ball and said socket, therebeing a central aperture through said ball for the passage of wires to the lamp, a handle on said sleeve by which it maybe rotated and means to prevent the complete rotation of said sleeve.

7. An adjustable dental lighting fixture in which a lamp is supported at the outer end of a telescoping tube, the tube being polygonal in cross section and slidable in a forked arm which is frictionally secured to a disk mounted in an annular member pivotally attached to a base, said disk having yieldable frictional means which permit its rotation freely in one direction but resists its movement in the opposite direction, characterized by the fact that the lamp socket is connected to the tube by a universal joint comprising a sleeve closed at one end to form a socket, a ball which fits said socket, a plug one end of which fits said ball slidably mounted in said sleeve, a plug threaded into the open end of said sleeve, a coil spring intermediate said plugs, whereby screwing in said threaded plug will increase the friction between said ball and said socket, there being a central aperture through said ball for the passage of wires to the lamp, a handle on said sleeve by which it may be rotated and means to prevent the complete rotation of said sleeve, said means comprising a peripheral groove formed in said ball, a pin in said groove, and a detent on said sleeve adapted to engage said pin. JASPER HANSEN. 

